Report discussing the results of an investigation to determine the low-speed power-off stability and control characteristics of a model of the Bell D-188A VTOL airplane. The static stability and control characteristics were generally satisfactory except above certain angles of attack and aileron effectiveness dropped off as the angle of attack was increased. Modifications for increasing the directional stability by altering the vertical tails are also described.

"In the course of a short flight program initiated to check the theory of Garrick and Watkins (NACA rep. 1198), a series of measurements at three stations were made of the oscillating pressures near a tapered-blade plan-form propeller and rectangular-blade plan form propeller at flight Mach numbers up to 0.72. In contradiction to the results for the propeller studied in NACA rep. 1198, the oscillating pressures in the plane ahead of the propeller were found to be higher than those immediately behind the propeller. Factors such as variation in torque and thrust distribution, since the blades of the present investigation were operating above their design forward speed, may account for this contradiction" (p. 999).

This report includes the description and results of an experiment evaluating the amount of adhesion existing between the liquid boron oxide and various materials used in engines.

Report presenting a graphic method for determining the composition and phases within a propellant tank when liquid oxygen is pressurized with nitrogen gas and some of the calculations involved. The assumed limiting conditions are that pressurizing gas flows adiabatically from the pressure tank and that equilibrium exists in the oxygen-nitrogen system. The experiment indicates that a series dilution of the oxidant occurs when nitrogen is used as a pressurizing gas, but a barrier at the liquid-gas interface would permit the use of nitrogen.

Report discussing various inlet design philosophies based on the results of testing at Mach numbers up to 5. The most ideal inlet design was found to be one with combined external-plus-internal compression due to problems noted with both external-only and internal-only inlets.

Report presenting an assessment of various inlet design philosophies assessed on the basis of recent experimental results at Mach numbers up to 5. The basic compression systems are compared for Mach 4.0 turbojet and hypersonic-cruise ramjet engines.The best-suited inlet for the Mach 4.0 turbojet engine is the combined external-plus-internal compression.

Report presenting an investigation of transpiration cooling in a preflight jet model consisting of a double wedge of 40 degrees included angle with a porous stainless-steel specimen inserted flush with the top surface of the wedge. Nitrogen and helium were used as coolants and testing was conducted for flow rates ranging from about 0.03 to 0.30 percent of the local weight flow. The helium coolant required only about one-fourth to one-fifth the coolant flow weight as the nitrogen coolant for the same amount of heat-transfer reduction.

Report presenting testing of a five-stage rocket-propelled model flown to a Mach number of 15.5 and an altitude of 98,200 feet. Temperatures were measured at six stations along the inside surface of the blunted conical nose with a total angle of 29 degrees. Experimental and theoretical values were similar at the first temperature measuring station, but the experimental results became increasingly greater than the theoretical values at rearward measuring stations.

Report presenting a free-flight investigation of the zero-lift rolling effectiveness of air-jet spoilers on an unswept flexible wing over a range of Mach numbers. Testing was made to determine the relative effectiveness of air-jet spoilers at leading-edge and trailing-edge locations. The leading-edge jet spoiler exhibited near-zero effectiveness at transonic speeds and had a roll reversal between Mach numbers 0.93 and 1.35.

Report detailing an investigation of the aerodynamic characteristics of a wing-propeller combination with the propeller rotating in the wing-chord plane of a two-dimensional wing. Total static lift was measured with and without the wing for a 3-foot-diameter propeller, while the effects of a ground plane on the static lift of the wing-propeller combination were measured with a 2-foot-diameter propeller. Results regarding static testing, forward speed tests, and propeller loads are provided.

Report presenting an investigation of several combustor configurations to determine if the length of the engine could be reduced. Testing indicated that when using a highly reactive fuel in the low subsonic region of the diffuser, part of the engine length can be eliminated.

"Existing data on the errors involved in the measurement of static pressure by means of static-pressure tubes and fuselage vents are presented. The errors associated with the various design features of static-pressure tubes are discussed for the condition of zero angle of attack and for the case where the tube is included to the flow. Errors due to variations in the configuration of static-pressure vents are also presented" (p. 1).

From Summary: "A preliminary investigation was conducted to determine the altitude performance of pentaborane and a blend fuel of 64.2 percent pentaborane in JP-4 fuel in a tubular combustor of a current production type turbojet engine. Deposits on the liner barrel and dome were virtually nonexistent. The combustion efficiency of 90 to 94 percent for pentaborane and approximately 90 percent for the blend. Outlet temperature profiles were marginal; however, the developed combustor provided lower pressure losses than obtained in conventional combustors."

Report discussing the influence of forces and moments on a fighter-bomber airplane with an open bomb bay and on two bluff bomb shapes in various positions below the fuselage and plane of symmetry. The wing was found to have a noticeable effect on bomb forces and that bluff bombs affect the longitudinal characteristics of the wing-fuselage combination.

Compendium presenting a comprehensive integration of available aerodynamic design information on axial-flow compressors. The subjects of the first volume of this investigation are objectives and scope, compressor design requirements, compressor design system, potential flow in two-dimensional cascades, and viscous flow in two-dimensional cascades.

"Available experimental two-dimensional-cascade data for conventional compressor blade sections are correlated. The two-dimensional cascade and some of the principal aerodynamic factors involved in its operation are first briefly described. Then the data are analyzed by examining the variation of cascade performance at a reference incidence angle in the region of minimum loss" (p. 1).

Chapters XI to XIII concern the unsteady compressor operation arising when compressor blade elements stall. The fields of compressor stall and surge are reviewed in Chapters XI and XII, respectively. The part-speed operating problem in high-pressure-ratio multistage axial-flow compressors is analyzed in Chapter XIII. Chapter XIV summarizes design methods and theories that extend beyond the simplified two-dimensional approach used previously in the report. Chapter XV extends this three-dimensional treatment by summarizing the literature on secondary flows and boundary layer effects. Charts for determining the effects of errors in design parameters and experimental measurements on compressor performance are given in Chapters XVI. Chapter XVII reviews existing literature on compressor and turbine matching techniques.

Report presenting an investigation in the transonic pressure tunnel to determine the afterbody pressure distribution and fin loading characteristics of two configurations of the TX-21 special weapon. The only different in the two configurations was the nose contour, with one having a hemispherical-flat shape and one with a double-radius ogive-flat shape. Results regarding the pressure port, fin loads, and force measurements are provided.

Memorandum presenting tests at two supersonic speeds to obtain experimentally the aerodynamic damping characteristics of a control surface on a two-dimensional wing. The control surface had a chord of 1.67 inches and a span of 7.25 inches and was supplied in three materials with different mass, inertia, and stiffness properties. Results regarding the presentation of data and comparison with theory and comparison with control-surface data for a triangular wing are provided.

Report presenting an investigation in the transonic blowdown tunnel to determine the effects of variations in inlet lip swagger from 0 to 60 degrees on the internal-flow characteristics of an unswept semielliptical scoop-type air-inlet model without boundary-layer control. Tests were made for a range of Mach numbers and mass-flow ratios. Results regarding the flow over the fuselage nose, total-pressure recovery at inlet, flow distortions at inlet, and inlet-design considerations are presented.

Report presenting an investigation of the static longitudinal-stability characteristics of a 45 degree sweptback wing-fuselage configuration with and without a sweptback horizontal tail for a range of angles of attack and Mach numbers. Special focus is given to the pitching-moment characteristics, location of the aerodynamic center, and slope of the lift-coefficient curve.

Effect of variation of combustion chamber length and inlet temperature on low pressure-loss sea level afterburner. A 70-percentage-point reduction in combustion efficiency resulted when the combustion-chamber length was reduced from 62 to 10 inches.

Report presenting an investigation made to determine experimentally the effects of two types of trailing-edge controls on the aerodynamic characteristics of a wing-body combination consisting of a 4-percent-thick wing of rectangular plan form and a slender body of revolution. The variations of lift coefficient with angle of attack of the flap-wing-body combination and spoiler-wing-body combination were generally nonlinear. Results regarding the trailing-edge flap control and trailing-edge spoiler controls are provided.

Report presenting an investigation of a swept-wing supersonic bomber configuration in the 4- by 4-foot supersonic pressure tunnel. Testing occurred at Mach numbers of 1.41 and 2.01 and a designated Reynolds number based on the wing mean aerodynamic chord. The model had a tapered wing with an aspect ratio of 3.5, a taper ratio of 0.2, a thickness ratio of 5.5 percent and 47 degrees sweep of the quarter-chord line. The investigation included the longitudinal and lateral force characteristics and various combinations of its components, including several jet nacelle installations.